Answer and Explanation:
1) In the position "P" the sun´s solar altitude would be the highest in Rockville, Maryland. At this point, it is summer in the northern hemisphere, and the sun is heating directly to the cancer tropic. Maryland is near this tropic, so position"P" could be considered the season in which the sun would be highest in relation to this point.
2) The earth at position V is experiencing winter in the northern hemisphere because the angle of sunlight is more indirect in this hemisphere. It is summer in the hemisphere that is inclined towards the sun and winter in the other hemisphere which is inclined far from the Sun. The hemisphere that is inclined towards the Sun is hotter because sunlight travels more directly to the Earth's surface and less light is scattered through the atmosphere. This means that whenever it is summer in the southern hemisphere, it is winter in the northern hemisphere. The hemisphere that is inclined towards the Sun has longer days and shorter nights. That is why during the summer the days are longer than during the winter.
3) In position V the sun´s path through the sky would be the highest in Australia. At this point, it is summer in the southern hemisphere, which means that the sun is heating the earth directly in the Capricorn tropic. This tropic passes straight through Australia, so this is the position in which the sun would be the highest in this country.
4) In positions U and D the earth experiences 12 hours of daylight and 12 hours of darkness. At these two points, the sun´s rays reach the equator at approximately the same angle every day. This is why there are no seasons at this latitude. Every single day of the year the equator receives about 12 hours of sunlight and 12 hours of darkness.